Brownian motion is the random motion of molecules in a gas or fluid due to the kinetic energy of the molecules. The kinetic energy, and thus the motion, of a molecule is directly related to its temperature, with a warmer molecule having more kinetic energy. The kinetic energy E of a molecule, measured in joules, is given by the formula:E=3/2k*T where T is the absolute temperature, in degrees Kelvin, of the molecule and k is the Boltzmann constant of 1.38*10−23 J/K. In a gas or fluid at room temperature of about 23 degrees Celsius, or 296K, a single molecule has kinetic energy of about 6.13*10−21 J.
Since the discovery of Brownian motion, many attempts have been made to design an apparatus that “taps into” the kinetic energy of molecules, using it as fuel to generate electricity, to propel a structure, or to perform other tasks. Such an apparatus must itself be subject to Brownian motion and therefore must be, or have components that are, microscopic or smaller in size. A Brownian-level apparatus was only theorized until the recent advent of technologies, such as microelectromechanical systems (“MEMS”) technology, that allow the construction of discrete articles at a suitably small scale. In one recent potential solution, U.S. Pat. No. 7,495,350 describes an array of beams measuring only a few nanometers across, wherein a particle that collides with a beam imparts some of its kinetic energy onto the beam, causing the beam to bend and then oscillate as it returns to its original position. The motion of the beam generates a small but measurable current in attached circuitry.
It would be advantageous to provide a device that converts the Brownian motion of molecules into rotational or revolving movement, in order to efficiently produce electricity as well as to directly operate pumps, wheels, axles, and other devices requiring rotational motion. One well-known example is the generically-termed “Brownian motor,” which includes a paddle wheel connected to a ratchet and pawl. The ratchet and pawl theoretically restrict the rotation of the paddle wheel to one direction, so that impacts of molecules on the paddle wheel's paddles cause one-way rotation of the wheel in discrete steps. This design has two primary drawbacks. Most importantly, it has been shown that the ratchet and pawl must also be at the nanoscale and are therefore also subject to Brownian motion. As a result, when the paddle wheel, ratchet, and pawl are at the same temperature, there is no net motion of the paddle wheel, and in fact the pawl is subject to failure that causes the paddle wheel to rotate in the opposite direction. The pawl and ratchet must be maintained at a lower temperature than the paddle wheel, which requires external application of energy to the system. The other main drawback is that, assuming a functioning device, the paddle wheel moves in discrete increments rather than moving continuously. A nano-scale engine that rotates or revolves substantially continuously without a temperature gradient is needed.
Therefore, it is an object of this invention to provide an apparatus for converting the kinetic energy of a molecule into useful work. It is a further object that the apparatus generate useful work from the Brownian motion of molecules in a gas or fluid. It is a further object that the apparatus generates the work through rotational or revolving motion. It is another object of the invention to provide an apparatus that converts the kinetic energy of molecules into electricity. It is another object of the invention to provide an apparatus that converts the kinetic energy of molecules into rotational motion for powering a rotary device. It is a further object that the apparatus power a nano-scale rotary device. It is still another object of the invention to provide an apparatus that moves, in a substantially controlled manner, due collisions with surrounding molecules. It is a further object of the invention to use the movement to transport a material along a path.